Multi-input multi-output (MIMO) technology has made a tremendous progress from the point-to-point single link to single-cell multi-user after almost ten years of development. With the advance of next generation mobile communication technology and standards, the MIMO technology has developed from the laboratory to the practical application, and the next generation wireless technology verification system adopting the MIMO technology effectively verifies the advantage of high frequency spectrum capacity which can be provided by the MIMO technology. However, the MIMO technology in an extended multi-cell system also has a problem of other-cell interference (OCI) in the multi-antenna multi-cell. Many interference suppression techniques of single-user MIMO and multi-user MIMO can be extended to the multi-cell system to be studied, wherein some methods are based on the interference suppression techniques of single-user MIMO and multi-user MIMO, and the methods are a class of research methods used more often in the current multi-cell MIMO.
In theory, adopting the MIMO technology has a strong appeal; however, in a commercial cellular system, the interference among cells in a network, since the MIMO technology is introduced, is still very complex, and it is also a problem for a cellular MIMO system to face inevitably. Especially, in a downlink system, the pressure of interference suppression that a base station side is faced with is very large due to the limitation of processing capacity of a terminal. Therefore, gain of the system capacity provided by the MIMO is greatly reduced in a multi-cell environment. Traditional multi-cell interference elimination methods (such as soft frequency multiplexing, sectoring and spread spectrum method) is not very effective for the multi-cell MIMO system due to some limitations of the methods themselves, which is obviously not beneficial to suppressing the communication interference.